Web dispatch service

ABSTRACT

A system and method for accessing an application server includes sending a service command from a requestor to a dispatch server, processing the service command on the dispatch server, translating the service command on the dispatch server into an application request to the application server, wherein the translating is based on a service definition stored on the dispatch server, and processing the application request. In one embodiment, the dispatch server includes a dispatch processor that is further programmed to manage a user interface, wherein the user interface includes a service registration interface, a service modification interface, and a service deletion interface.

FIELD OF THE INVENTION

The present invention is related to software application management, andmore particularly to the translation of simple service requests intocomplex web links.

BACKGROUND OF THE INVENTION

Computer science has forever grappled with solving the following,contrary statements: systems become more brittle as intelligence isdistributed, but systems also become less scalable as intelligence iscentralized. How can we enjoy the benefits of distributed scalabilitywith the superior availability and reliability of centralization? Therehas been a steady evolution of tools and methods to answer thisquestion. The advent of libraries and routines that could be included(linked) in multiple applications migrated to shared libraries thatmitigated the need to rebuild every application when a referencedroutine was changed. Later, the concept of objects promoted reuse andportability by only exposing necessary methods and properties to theusing application. Today, we routinely use object brokers that provideobjects as services to applications, further insulating developers fromthe intricacies of a desired capability while still providing thefunctionality required.

Another current example is the use of stored procedures to accessdatabase information rather than using specific structured querylanguage (SQL) commands in a given application. This moves a largeportion of database intelligence out of the application and into thedatabase server, which effectively centralizes more of the intelligencewhile distributing the capability. A change can be made to thecentralized stored procedure to fix a bug or add functionality to allapplications that use the procedure without requiring a change to eachapplication itself.

Today, however, we have no similar mechanism for minimizing intelligencerequired by one web application that needs to access the services ofanother web application. For example, to display employee information ina web application, one could use an employee lookup program. However, touse that application, one must know things such as the server theapplication is currently running on, the path to and name of theapplication, and what information the program needs to provide thedesired service. All of this information may be encoded in a UniversalResource Locator (URL) or link. This is not necessarily a lot ofinformation to maintain, but if any of that information changes, thelink will break. As the number of copies of this link grow, and if thelink itself becomes more complex, then the maintenance could become moresignificant.

Clearly, the information required by a web application can be even moreinvolved in certain circumstances. For example, enabling applicationswith Top Tier's Drag and Relate (DnR) capability, while powerful, canrequire significantly more intelligence in the enabled application.Additionally, most DnR Enabled Applications (DEAs) need to know whenthey are DnR enabled, since displaying DnR links outside of DnR awareenvironments could be confusing to the user, and simply won't work ifactivated. Further, DEAs must encode information into the DnR links sothe DnR servers understand what to do with the DnR link. Again, if anyof that information changes, then the application will break. Thisapproach becomes untenable in a large enterprise with many applicationscross-linking each other.

For the reasons stated above, and for other reasons stated below whichwill become apparent to those skilled in the art upon reading andunderstanding the present specification, there is a need for the presentinvention.

SUMMARY OF THE INVENTION

One aspect of the present invention provides a dispatch server thatincludes a data store having one or more entries that containapplication service information, and a dispatch processor operativelycoupled to the data store, wherein the dispatch processor is programmedto translate an application service to an application address. In someembodiments, the dispatch processor is further programmed to manage auser interface, wherein the user interface includes a serviceregistration interface, a service modification interface, and a servicedeletion interface.

Another aspect of the present invention provides a method for addressingan application server. The method includes sending a service commandfrom a requester to a dispatch server, processing the service command onthe dispatch server, translating the service command on the dispatchserver into a application address, redirecting the application addressto the requester, and accessing the application server. In someembodiments, the application address is a complex address. In someembodiments, the processing of the service command includes validatingthe service command. In some embodiments, the processing of the servicecommand includes checking the service command for parameters.

Another aspect of the present invention provides a system that includesa dispatch server and a service user. The dispatch server includes adata store, and a processor programmed to translate a service requestinto an application command. The service user is operatively coupled tothe dispatch server, wherein the service user sends the service requestto the dispatch server, and wherein the dispatch server translates theservice request and sends the application command to the service user.

Another aspect of the present invention provides a system that includesa dispatcher and an service provider. The dispatcher includes a datastore, and a processor programmed to translate a service request into anapplication address and manage a user interface, wherein the userinterface includes a service registration. The service provider isoperatively coupled to the dispatcher, wherein the service providerregisters its services with the dispatcher through the user interface.

Another aspect of the present invention provides a method forcentralized management of complex web links on a web dispatch provider.The method includes storing application service definitions and complexweb link data in a centralized database of the web dispatch provider,receiving service requests from a browser, sending redirectedapplication requests to a browser, and changing the complex web linkdata in the centralized database without changing the applicationservice definitions.

Another aspect of the present invention provides a method forregistering services on a web dispatch server. The method includessending a registration request from an application server to the webdispatch server, the registration request having a first service name,processing the registration request on the web dispatch server,registering a new service for the registration request on the webdispatch server, the new service having a second service name, andstoring the new service in a web dispatch database, such that a user canaccess the new service of the application server by sending a servicerequest to the web dispatch server.

BRIEF SUMMARY OF THE DRAWINGS

In the following drawings, where the same number reflects similarfunction in each of the drawings,

FIG. 1A is a high-level component view of a dispatch server according toone embodiment of the present invention;

FIG. 1B is a high-level component view of a dispatch server and anadditional server according to another embodiment of the presentinvention;

FIG. 2 is a detailed view of a set of entries in a data store of thedispatch server according to one embodiment of the present invention;

FIG. 3A is a block diagram illustrating a system that includes adispatch server, an application server, and a client, according to oneembodiment of the present invention;

FIG. 3B is a block diagram illustrating a system that includes adispatch server, an application server, and a client, according toanother embodiment of the present invention;

FIG. 3C is a use-case diagram illustrating various use cases indifferent embodiments of the present invention;

FIG. 4 is a flow chart illustrating a method for translating servicerequests into application requests according to one embodiment of thepresent invention;

FIG. 5A is a flow chart illustrating a method for managing servicesthrough a user interface of a dispatch server according to oneembodiment of the present invention;

FIG. 5B is a continuation of the flow chart shown in FIG. 5Aillustrating a method for managing services through a user interface ofa dispatch server according to one embodiment of the present invention;

FIG. 6 is a textual view of an example of a service request sent to adispatch server according to one embodiment of the present invention;

FIG. 7 is a textual view of an example of a translation of a servicecommand into an application command according to one embodiment of thepresent invention;

FIG. 8 is a textual view of an example of service invocation compressionaccording to one embodiment of the present invention;

FIG. 9 is a textual view of an example of service request translationand parameter formatting according to one embodiment of the presentinvention;

FIG. 10 is a textual view of an example of service request translationand parameter defaults according to one embodiment of the presentinvention;

FIG. 11 is a textual view of an example of service request and methodtranslation using form data according to one embodiment of the presentinvention; and

FIG. 12 is a textual view of an example of service request and methodtranslation parameter transparency according to another embodiment ofthe present invention.

DETAILED DESCRIPTION

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings which form a part hereof,and in which is shown by way of illustration specific preferredembodiments in which the inventions may be practiced. These embodimentsare described in sufficient detail to enable those skilled in the art topractice the invention, and it is to be understood that otherembodiments may be utilized and that logical, mechanical and electricalchanges may be made without departing from the spirit and scope of thepresent invention. In certain embodiments, reference is made to certainoutside technologies to exemplify the utility of these embodiments ofthe invention. These technologies are not associated with, or requiredby, these embodiments of the invention for operation, but are describedonly to demonstrate the flexibility and utility of these embodiments ofthe invention in various operating environments. The following detaileddescription is not to be taken in a limiting sense, and the scope of thepresent invention is defined by the claims.

INTRODUCTION

It is interesting to consider web pages and applications in terms ofobjects and transactions. One can consider a single, static web page asa simple object with a single method called “display my contents.” Themethod is invoked via the web link for that page. Web pages generated byan application are just slightly more complex objects that now includezero or more properties. These properties are sent to the application inthe link itself or through other data that a browser can send to thelink's destination. Thus, the method of an application is just a bitmore complex and may be called something like “display my contents basedon my properties.”

By the nature of the environment, web applications aretransaction-based. A web application is nothing more than a collectionof web pages presented to a browser with a common look, feel, andpurpose. The web environment itself neither cares nor knows about anyapplication, and is, in fact, stateless. The web is only concerned withrequests and responses. Using an employee lookup program (i.e. whitepages) example, an entry page might present a list of many things thatcan be done, such as looking up an employee by last name (or byuser-name or employee number), or searching the phone book for phonenumbers, parts of names, etc. In fact, each of these capabilities is atransaction that may be executed independent of the others as long asthe correct information is passed to the right server.

This object and transaction orientation makes the web very flexible andpowerful. This same capability, however, can also cause reliability,availability, and scalability (RAS) issues in an enterprise if notcarefully managed. RAS issues have been around in the softwaredevelopment field for many years, and new technologies have evolved overtime to address them. Such technologies are less mature in the webenvironment. Certain embodiments of the present invention describedbelow apply some of the lessons learned in traditional softwaredevelopment to a web environment of linked objects and transactions.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1A is a high-level component view of a dispatch server comprising acomputer-readable medium for storing instruction according to oneembodiment of the present invention. In this embodiment, dispatch server100 is located on the World Wide Web, and includes data store 110 anddispatch processor 120. Dispatch processor 120 includes translator 130and service management (user) interface 140, and is operatively coupledto data store 110. Data store 110 has one or more entries that containapplication service information, and dispatch processor 120 isprogrammed to translate an application service request via translator130 into an application address. In this embodiment, service managementinterface 140 includes service registration 150, service modification160, and service deletion 170. Dispatch processor 120 is furtherprogrammed to manage service management interface 140. Dispatch server100 shown in FIG. 1A has various functionalities. In differentembodiments, dispatch server 100 includes functionalities forservice-to-application translation, service registration, serviceavailability, parameter formatting, parameter completion (or defaults),method translation, and source routing. Service-to-applicationtranslation enables a link to reference a service, rather than aparticular application with all its required parameters, etc. Serviceregistration allows new applications to register their services andusages. Service availability allows users to discover which services areavailable from different application providers. Service modificationallows applications to modify or delete their services afterregistration. Parameter formatting allows a link to contain parameterswithout knowledge of the required format of those parameters, and alsoallows support for different formatting of the same parameter fordifferent applications. Parameter completion allows links to includeonly a subset of all required parameters to a target application. Methodtranslation allows links to include parameters for target applicationswithout knowledge of the method required.

FIG. 1B is a high-level component view of a dispatch server and anadditional server according to another embodiment of the presentinvention. In this embodiment, service management interface 140 isincluded in a separate and distinct run-time server 101 than dispatchserver 100. Server 101 is operatively coupled to dispatch server 100.Server 101 includes processor 121. Processor 121 is programmed to manageservice management interface 140. This dual-server architecture improvesstability of the overall run-time system. One server, such as server101, may go down while the dispatch server 100 is still functional. Inthis scenario, applications could not register, modify, or deleteservices on server 101, but clients could still invoke services ondispatch server 100. Considering the potential high transaction-rate ofdispatch server 100, one embodiment includes a system with dispatchserver 100 as a large-scale server, and server 101 as a cheaper, smallerplatform.

In the embodiments shown in FIGS. 1A and 1B, dispatch server 100 is veryflexible, such that it can operate in many different types ofenvironments. Certain environments require specific application servicemessage protocols and language definitions. Dispatch server 100functions within these environments, wherein the application serversimplementing any specific protocols or service language definitions willinterface cleanly with dispatch server 100 during run-time operation.

FIG. 2 is a detailed view of a set of entries in a data store of thedispatch server according to one embodiment of the present invention. Inthis embodiment, data store 110 includes entries 180 through 190 thatcontain application service information about service₁ throughservice_(A). Entry 180 includes information about a first applicationservice 181 (service₁). The information of entry 180 corresponding toservice₁ 181 is contained within data entry 182 (data₁) through dataentry 183 (data_(B)). Data entries 182 through 183 include various datainformation about service₁ 181. Data entries 182 through 183 includesinformation that is specific to service₁ 181, and are referenced bydispatch processor 120 of dispatch server 100. In some embodiments, dataentries 182 through 183 include definitions for enablement anddisablement of service₁ 181. Service₁ 181 is a service that has beenregistered on dispatch server 100 by an application provider. Dataentries 182 through 183 can dynamically change over time, such that thedefinition of service₁ 181 is configurable. Entry 190 includesinformation about an A^(th) application service 191 (service_(A)). Theinformation of entry 190 corresponding to service_(A) 191 is containedwithin data entry 192 (data₁) through data entry 193 (data_(C)). Dataentries 192 through 193 include various data information aboutservice_(A) 191. Data entries 192 through 193 includes information thatis specific to service_(A) 191, and are referenced by dispatch processor120 of dispatch server 100. In some embodiments, data entries 192through 193 include definitions for enablement and disablement ofservice_(A) 191. Service_(A) 191 is a service that has been registeredon dispatch server 100 by an application provider. Data entries 192through 193 can dynamically change over time, such that the definitionof service_(A) 191 is configurable.

FIG. 3A is a block diagram illustrating a system that includes adispatch server, an application server, and a client, according to oneembodiment of the present invention. In this embodiment, system 200includes dispatch server 100, application server 210, and client 220. Insome embodiments, client 220 may also be an application server. Dispatchserver 100 is operatively coupled to both application server 210 andclient 220. Client 220 is operatively coupled to both dispatch server100 and application server 210. Application server 210 is operativelycoupled to both dispatch server 100 and client 220. System 200 providesclient 220 with the ability to address application server 210. Client220 sends service request 230 to dispatch server 100. Dispatch server100 processes service request 230 and translates service request 230into an application request 240. Dispatch server 100 redirectsapplication request 240 back to client 220. Client 220 receivesapplication request 240 and forwards it as application request 280 toapplication server 210. Application server 210 processes applicationrequest 280, and sends application response 270 to client 220. In system200, client 220 is an end-user.

This embodiment provides several advantages. First, system 200 is morereliable, because the transaction time between client 220 and dispatchserver 100 is quite small. Dispatch server does not need to maintainstate information about its transaction with client 220, and thereforethe transaction rate can be quite high. Second, system 200 provides aclearer security model, because client 220 directly invokes applicationrequest 280 to application server 210 (i.e. dispatch server 100redirects application request 240 back to client 220, rather thansending it to application server 210). This provides a clearer securitymodel and eases cookie management.

To further exemplify the advantages of this embodiment, we can use twoanalogies. The first analogy is that of a taxi service. Aside from nothaving to drive, a key benefit is that we don't need to know where adestination is, or how to get there. We can just hop in and ask to betaken to a certain location, and a while later, we arrive there. Forless common destinations, we may have to provide a specific address tothe taxi driver, but we still don't have to know how to get there. And,for generic locations, we may not even need to know the name of thelocation. For example, we might just say to the taxi driver, “Take me tothe closest book store.” This is an example of how we minimize theinformation we need to do something (i.e. get to a destination) byrelying on another source (i.e. the taxi driver) for that information.

The second analogy is that of a vacation in Mexico. Let's say you decideto vacation in Mexico and don't speak Spanish, but your travelingcompanion does. While in a restaurant, you need to use a restroom (whichyou are quite certain that the restaurant has). You ask your travelingcompanion for help. She tells you how to ask for the restroom inSpanish, and further informs you that you can ask a clerk in therestaurant, such that the clerk will understand your request, and alsobe able to give you a correct response (as to how to find the restroom).There are at least two important points in this analogy: (1) yourtraveling companion did not ask for you, but told you how to ask, and(2) your traveling companion also told you where to ask. By correctlyformatting (and redirecting) an application request in this embodiment,the dispatch server is basically telling you how and where to ask. Byreturning the application request in a redirect message, the dispatchserver is letting the client make the request, not actually calling thetarget application server directly.

In some embodiments, application requests 240 and 280 are complexaddresses. In other embodiments, service request 230 includes a URL. Inother embodiments, the processing of service request 230 on dispatchserver 100 includes validating service request 230, and checking servicerequest 230 for parameters.

In the embodiment shown in FIG. 3A, application server 210 also sendsuser interface commands 250 to dispatch server 100. These user interfacecommands 250 will be processed by the user interface of dispatch server100, and then user interface responses 260 will be sent back toapplication server 210. In this way, application server 210 can registerservices on dispatch server 100. In another embodiment, applicationserver 210 can modify and delete services on dispatch server 100. Inthis way, service definitions can change without having to changeservice requests. Dispatch server 100 has centralized management ofcomplex web links, such that client 220 sends the same service request230 to dispatch server 100 after the service definitions have changed.In some embodiments, client 220 sends additional commands to dispatchserver 100 to discover which services are currently available.

FIG. 3B is a block diagram illustrating a system that includes adispatch server, an application server, and a client, according toanother embodiment of the present invention. In this embodiment, system201 includes dispatch server 100, application server 210, and client220. Dispatch server 100 directly sends application request 240 toapplication server 210. Application server 210 processes applicationrequest 240, and sends application response 270 back to dispatch server100. Dispatch server includes an amount of state information, so that itcan send application response 271 to client 220. In this case, dispatchserver 100 acts substantially similar to a reverse proxy. Client 220never needs to know the exact address of application server 210, nordoes it need send requests to application server 210. Dispatch 100handles all of the transactional work with application server 210.Client 220 only needs to send simple service requests to dispatch server100, and in one embodiment, these requests can easily be bookmarked asURL favorites on client 220.

FIG. 3C is a use-case diagram illustrating various use cases indifferent embodiments of the present invention. In this embodiment,use-case diagram 281 shows use cases involving a service user 283 and aservice provider 282. In one use case, service provider 282 implementsuse 292 for use case 284 to register a service on a dispatch provider.User interface 291 aids in the registration process. Database 290 isupdated to include the new service. In another use case, service user283 implements use 296 for use case 288 to invoke a service on thedispatch provider. Dispatcher 289 handles the service request sent fromservice user 283, and database 290 is used to query information aboutthe requested service.

In another embodiment, service user 283 implements use 295 for use case287 to discover available services on the dispatch provider. Userinterface 291 aids in the discovery process, and database 290 is used toquery information about available services on the dispatch provider.

In another embodiment, service provider 282 implements use 293 for usecase 285 to modify an existing service on the dispatch provider. Userinterface 291 aids in the modification process, and database 290 isupdated for the modified service.

In another embodiment, service provider 282 implements use 294 for usecase 286 to delete an existing service on the dispatch provider. Userinterface 291 aids in the deletion process, and database 290 is updatedto delete the indicated service.

FIG. 4 is a flow chart illustrating a method for translating servicerequests into application requests according to one embodiment of thepresent invention. In this embodiment, flow diagram 300 begins with step310, when dispatch server 100 receives a service request from a browser.In step 320, dispatch server 100 parses the request to determine theformat and contents of the request. At checkpoint 330, dispatch server100 determines if the service request is valid. If it is not, an errormessage is displayed, and an error is returned to the browser. If theservice request is valid, dispatch server then checks if the serviceinvoked by the service request is in data store 110 at checkpoint 340.Data store 110 contains service data entries (definitions) for each ofthe services registered on dispatch server 100. If the service is notlocated in data store 110, an error message is displayed, and an erroris returned to the browser. If the service is in data store 110, thendispatch server next determines if the service is available atcheckpoint 350. If the service is not available, an error message isdisplayed, and an error is returned to the browser. If the service isavailable, step 360 then resolves the service request into anapplication request. To do this, dispatch server 100 references datastore 110 to determine the service definitions that are relevant to theinvoked service. At checkpoint 370, dispatch server 100 determines ifthe service request contains any parameters. If the request does notcontain any parameters, then dispatch server redirects the applicationrequest to the browser in step 430. If the request does containparameters, then dispatch server determines if the parameters are validfor the indicated service at checkpoint 380. Again, dispatch serverreferences data store 110 in determining if these parameters are validfor the particular service in question. If the parameters are invalid,an error message is displayed, and an error is returned to the browser.If the parameters are valid, dispatch server 100 processes theparameters in step 390. At checkpoint 400, dispatch server determines ifany of the parameters are POST method parameters. As will be describedin more detail below, parameters may be passed to an application servervia the POST method, which passes parameters in data (other than in theURL) that is sent to the application server. If there are no POST methodparameters, then dispatch server 100 redirects the application requestto the browser in step 430. If there are POST method parameters, thendispatch server 100 creates a form using these parameters in step 410.In step 420, dispatch server 100 returns the form with an invocation ofthe onload event that calls the form's submit method, and then redirectsthe application request (which includes the form) to the browser in step430. Flow diagram 300 ends with step 450.

FIGS. 5A and 5B (hereinafter referred to collectively as FIG. 5) show aflow chart illustrating a method for managing services through a userinterface of a dispatch server according to one embodiment of thepresent invention. In this embodiment, user interface requests can beused to add, delete, and modify services and service definitions on thedispatch server. Flow diagram 500 begins with step 510, when a userinterface request is received by the dispatch server. As discussedearlier, this user interface request will be sent to the dispatch serverfrom an application server. In step 520, a welcome page with links willbe displayed on dispatch server 100. At checkpoint 530, dispatch server100 determines if the user interface request has made a selection toview registered services on dispatch server 100. After such a selectionis made, dispatch server 100 displays all available services fromdatabase 110. Database 110 includes information for all currentlyregistered services on dispatch server 100.

At checkpoint 660 of FIG. 5, dispatch server 100 determines if the userinterface request includes a request to add a new service. If therequest is to add a new service, step 670 enters the name of the newservice from the request. In one embodiment, the request is parsed toextract the new service name. Step 680 checks database 110 for a similarservice name. Database 110 includes information for all currentlyregistered services on dispatch server 100. At checkpoint 690, dispatchserver 100 determines if the new service name is unique from otherservice names currently registered in the system. If the name is notunique, control is returned to step 670 to enter another name for thenew service. If the name is unique, then step 700 enters the servicedefinition from the user interface request. In one embodiment, the userinterface request is parsed to extract the service definition. After theservice definition has been entered, the new service is registered instep 710 into database 110. Database 110 at this point contains theservice definition for the new service. At checkpoint 720, dispatchserver 100 determines if the service has parameters. If it does not,then dispatch server 100 determines if any more services are to be addedat checkpoint 730. If the service does have parameters, then theparameters are entered in step 740. In one embodiment, the userinterface request is parsed to extract the parameters. In step 750, thenew parameters are registered into database 110 for the new service.

At checkpoint 550 of FIG. 5, dispatch server determines if the userinterface request includes a request to edit an existing service. If theuser interface request includes such a request, then step 560 queriesdatabase 110 to display the current service definition for the givenservice. In one embodiment, the user interface request is parsed toextract service information. At checkpoint 570, dispatch server 100determines if the user interface request includes a request to delete aservice. If it does not, the service definition is edited at step 590.Then, at checkpoint 600, dispatch server 100 determines if theparameters are to be edited. If they are not, then the service isupdated in step 610 and database 110 is also updated for the editedservice. If the parameters are to be edited at checkpoint 600, thencurrent parameters are displayed in step 620. At the next checkpoint630, dispatch server 100 determines if a parameter is to be deleted. Ifnot, then the parameter definitions are edited in step 650, and theservice is updated in step 610 (such that database 110 is updated). Ifthe parameter is to be deleted, then the parameter is removed fromdatabase 110 in step 640. If dispatch server 100 determines that theservice is to be deleted at checkpoint 570, then the enter service isremoved from database 110 in step 580.

FIG. 6 is a textual view of an example of a service request sent to adispatch server according to one embodiment of the present invention. Inthis embodiment, the core feature provided by the dispatch server is theability to abstract the details of a specific web address into a genericservice definition that hides much of the intelligence typicallyrequired in a link. Service request 800 shows the basic format forlinking to a web application that is defined as a dispatch service.Textual element 801 of service request 800 is the name of the dispatchserver. Textual element 802 of service request 800 is the name of aregistered service on the dispatch server. Textual element 803 ofservice request 800 contains the parameters and/or values required forthe indicated service. Thus, in this embodiment, a service request 800sent to a dispatch server includes a dispatch server name, a registeredservice name, and parameter values. In some embodiments, the servicerequest includes only a dispatch server name and a registered servicename.

FIG. 7 is a textual view of an example of a translation of a servicecommand into an application command according to one embodiment of thepresent invention. In this embodiment, an example of an employee lookupprogram is used to demonstrate the service-to-application translationcapabilities of the dispatch server. Service command 810 is translatedinto application command 820 by a dispatch server. Textual element 811of service command 810 is the communication protocol. Textual element812 of service command 810 is the name of the dispatch server. Textualelement 813 of service command 810 is the name of a registered employeelookup service on the dispatch server. At some previous time, the clientwho has sent this service command has discovered this service by name onthe dispatch server. Textual element 814 of service command 810 is theparameter required by the service indicated by textual element 813. Thisparameter can be sent directly in service command 810. The dispatchserver of this embodiment of the invention translates the servicecommand 810 into application command 820. Application command 820includes textual elements 821, 822, 823, and 824. Textual element 821 isthe communication protocol. Textual element 822 is the name of theserver running the particular application. Application command 820 issent to this server. Textual element 823 is the path and name of theapplication running on the server. Textual element 824 is theinformation that the application needs in order to return the desiredinformation for employee number 48.

In this embodiment, service registration and request redirectionfunctionalities allow the dispatch server to translate service command810 into application command 820. Before service command 810 arrives atthe dispatch server, the employee lookup application owner must registerthe “employee_lookup_by_workno” service with the dispatch server,including a required parameter “emp” that designates a single employeenumber. Additionally, during registration, dispatch server must storedata for the given service indicating that the program “emp/default.asp”on server “iisprod” must be invoked with a single parameter “emp.”Parameters may be passed to an application using a GET method, and alsomay be passed using a POST method. The GET method passes parameters toan application directly in the address (e.g. URL). The POST methodpasses parameters in other data that is sent to the application. In thepresent embodiment, the parameter “emp” is passed using the GET method.In some embodiments, the dispatch server also stores data for the givenservice that associates a description and owner with the service, andthis information is provided to clients during service discovery.

After service registration, a client sends service command 810 to thedispatch server. After service command 810 is translated intoapplication command 820 by the dispatch server, application command 820is redirected back to the client. By sending the client back theapplication command in a redirect message, the dispatch server lets theclient make the request to the application server directly. Thisapproach has certain benefits. After the dispatch server has translatedthe request, it is basically done. This involves a simple database queryand some possible data formatting, all of which can be done quitequickly. The dispatch server then sends a small amount of data back tothe client. It does not have to wait for the target application torespond, nor does it route the results from the target application backto the client. This means that the dispatch server does not need tomaintain any state information, and that the dispatch server will beable to handle many service commands per second. Further, theapplication command redirection approach minimizes the network path (andtraffic) for the results to get from the target application back to theclient. It also is important for usage logging, access tracking, andsecurity management.

In another embodiment, the dispatch server directly sends applicationcommand 820 to the application server, and routes an applicationresponse back to the client. In this embodiment, the dispatch serverwould need to maintain some state information.

In yet another embodiment, the service registration process is at leastpartially automated. In this embodiment, a dispatch interface isdesigned so that an application can register itself for all of itsavailable services. In one specific embodiment, the Extensible MarkupLanguage (XML) provides a simple, hierarchical messaging protocolwhereby the required service components are described, filed, andupdated by existing applications.

In yet another embodiment, the dispatch server provides currentlyavailable service information to clients who send service inquiryrequests to the dispatch server. In this way, clients find out about(i.e. discover) services offered by the dispatch server. In one specificembodiment, a client can inquire about a reserved service, such as aservice named “info,” from the dispatch server. After receiving thisinquiry, the dispatch server would return information about itself tothe client. Further, if the “info” service is called with a “services”parameter (which is a reserved parameter name for the reserved service“info”), then the dispatch server will directly respond to the clientwith a list of published services, their names, required parameters, adescription, and human contact information. In another embodiment, theservice inquiry (i.e. discovery) process is also at least partiallyautomated. In this embodiment, an XML-enabled interface is provided,such that clients inquire which services are available, and how toaccess them.

FIG. 8 is a textual view of an example of service invocation compressionaccording to one embodiment of the present invention. In this exampleembodiment, service invocation 830 is compressed into a smaller serviceinvocation 840. Both service invocations 830 and 840 of the presentembodiment are in Uniform Resource Locator (URL) format. It is widelyknown that some web browsers and servers limit the length of a URL to255 characters, which in turn limits the amount of information that canbe passed to an application via the path or GET method. Because the webdispatch service limits the amount of information required in the links,the service also has the effect of compressing a URL (such as in aservice invocation), which is to say that more information can beimplicitly communicated in less space. Service invocation 830 includestwo GET method parameters, “var1” and “var2”. The “var1” parameter isset equal to “value1” and the “var2” parameter is set equal to “value2.”Service invocation 840 takes full advantage of URL compression viaparameter translation. The values “value1” and “value2” are passeddirectly in the service invocation, thus making service invocation 840more compact.

Additional decoupling is available between calling and targetapplications if the dispatch server provides parameter formatting. Thisnot only removes the burden of parameter formatting from the callingapplication, but also eliminates the need to possibly support multipleformatting of the same parameter for different target applications. FIG.9 is a textual view of an example of service request translation andparameter formatting according to one embodiment of the presentinvention. In this embodiment, service request 850 is translated intocontent request 860, such that one of the parameters of the servicerequest is properly formatted. Service request 850 includes a DnRservice. Although FIG. 9 (and some of the other figures and portions ofthe present specification) make reference to DnR capabilities of TopTier's Drag and Relate, these figures are used only as examples to showthe utility of these embodiments of the present invention in variousoperating environments. Top Tier's Drag and Relate technologies are inno way associated with, or required by, these embodiments of the presentinvention. They are shown in the figures and further described only toexemplify the flexibility of use of a dispatch server in certainoperating environments of these embodiments.

To send content request 860 to a DnR server, the DnR server requires theemployee number to be an 8 digit integer with zero left padding. (Inthis scenario, DnR server is a content server.) In this instance, theformatting is performed by the dispatch server, and the formatting codeis eliminated from the employee lookup program (i.e. client). FIG. 9shows the format of the call to the dispatch server and the URL that isre-directed back to the client. We assume that the service“dnr_return_workno” has been previously registered with the dispatchserver and in doing so, the format of the parameter is specified as an 8digit integer with zero left padding. Content request 860 is a DnR link,where “hrnp://” is the Hyper Relational Navigation Protocol (for TopTier Drag and Relate). “ntitsqaw03:9997” is the server (on port 9997 inthis case). “BUS1065” is the name of the object. “OBJECTKEY” is the nameof the objectid. And “00000048” is the parameter formatted that is beingdrag and related for employee number 48.

It should be noted that the example shown in FIG. 9 is somewhatartificial, in that DnR links in DEAs (DnR Enabled Applications) areonly meant, as the name implies, to be drug to a DnR aware server andnot simply clicked on as are other HTML links. Therefore, the clientcannot return content request 860 as specified above. The link shownmust be available as is so it is dragable (i.e., since we don't actuallyclick on the link, it can't be sent to the dispatch server forinterpretation). In FIG. 10, we present another embodiment of thedispatch server and demonstrate a more legitimate way to engage thedispatch server to remove DnR intelligence from DEAs.

Another key feature of another embodiment of a dispatch server isaccepting a service request from a client that has only a subset of atarget application's required parameters. This is to say that thedispatch server can provide default parameters if they are omitted.Continuing with the example embodiment above in FIG. 9, our goal is toremove intelligence from the employee lookup program (i.e. client), yetstill allow it to be fully DnR enabled. The worker information isdynamic and must be passed to the employee lookup program in each call.However, the DnR information is static and constant across all calls.FIG. 10 is a textual view of an example of service request translationand parameter defaults according to one embodiment of the presentinvention. In this embodiment, service request 870 is translated intoapplication link 880. We define a variable DNR that if present (via theGET or POST method) indicates to a target application that it is in DnRmode. We can further require that the value of the DnR variable be theDnR enabled link that the application must display. In FIG. 10, theembodiment of the dispatch server's parameter completion feature furtherremoves intelligence from the calling application. In FIG. 10, we assumethat the service “employee_lookup_by_workerno_withDNR” has beenpreviously defined with two parameters, one being the required employeenumber (emp), and also a second optional parameter (DNR) with a defaultvalue of “hrnp://ntitsqaw03:9997/BUS1065/OBJECTKEY/#PARAM#emp”. Here,the “#PARAM#” string tells the dispatch server to substitute the valueof another, non-default parameter, which in this case is “emp” that hasa value of 48. When registering this application, we also expect thatthe default “DNR” parameter was specified to require left-zeroformatting.

FIG. 11 is a textual view of an example of service request and methodtranslation using form data according to one embodiment of the presentinvention. In this embodiment, the dispatch server is able to handle thecase when a target application (on a service provider) is expectingparameters via the POST method. Dispatch server translates servicerequest 890 into application link 900, wherein application link 900includes the required POST method parameters with the form's “action”variable set to the target application's URL. In addition, applicationlink 900 also includes an invocation of the “onload” event that callsthe form's “submit” method. As soon as the form is received by theclient from the dispatch server, it is immediately submitted, which isconsistent with the redirect method used with the GET and pathparameters (directly passed in the URL path) described in earlierembodiments of the invention. The two parameter values “value1” and“value2” are passed to the dispatch server via the path method have beentranslated to POST method variables via the form, and that a thirdparameter “var3” has been added as well. This third parameter isrequired by the application and automatically supplied by dispatch usingparameter completion with its default value, “value3”. In thisembodiment, additional bookmarking of applications is also allowed withthe type of form data shown in application link 900. Typically,applications requiring POST method parameters cannot be bookmarked (orsaved as a URL favorite), because there is no way to store theparameters in the URL, which is all that is saved in a bookmark. Byallowing the parameters to be specified in a URL and later converted viathe dispatch server to the expected POST method, an application thatpreviously did not support bookmarking now does.

FIG. 12 is a textual view of an example of service request, methodtranslation, and parameter transparency according to another embodimentof the present invention. In this embodiment, if path or parameterinformation is passed to the dispatch server for which no associatedparameters are listed, then the dispatch server will simply pass on thepath or parameter information in the same manner in which it wasreceived. This provides maximum flexibility for migrating links to takefall advantage of the dispatch service. In FIG. 12, service request 910having GET parameters (“var1” is implicitly provided by “value1,” and“var2” is explicitly provided as “value2”) is translated into POSTmethod application request 920. In this embodiment, “var2” is notdefined in the service database of the dispatch server, and thus it issimply passed along transparently as a parameter from service request910 into application request 920, while “value1” is translated into aPOST method parameter, and “value3” is supplied as a default value.

In another embodiment of the present invention, the dispatch serverprovides source routing. In this embodiment, service requests aretranslated into application requests just as before. However, during thetranslation process, the dispatch server determines the geographiclocation of the requesting client and one or more application serversthat provide the requested service. That is to say, there can be manyapplication servers in different geographic locations that provide therequested service. Source routing occurs when the dispatch serverdetermines the closest application server to the requesting client whentranslating a service request and redirecting an application requestback to the client. For example, in a specific embodiment, applicationservers in the United States, Italy, and Japan all provide a commonservice of “employee_stock_quoting.” A client in Italy sends a servicerequest for “employee_stock_quoting” to the dispatch server. Thedispatch server will achieve source routing by assessing the client'slocation (Italy), and determining that the nearest application serverthat provides the requested service is the one in Italy. The dispatchserver will redirect an application request back to the client, whereinthe application request includes the address of the application serverin Italy.

In another embodiment, the dispatch server uses a load-balancingstrategy when choosing the appropriate application server and therebycreating an application request. In this way, routing of requests isachieved to maximize the load-balancing strategy used by the dispatchserver. This occurs when multiple application servers in a givengeographic location provide the requested service. The dispatch serverimplements a load-balancing strategy to determine which applicationserver will handle the application request. In one embodiment, theload-balancing strategy includes a round-robin strategy.

CONCLUSION

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement which is calculated to achieve the same purpose maybe substituted for the specific embodiment shown. This application isintended to cover any adaptations or variations of the presentinvention. Therefore, it is intended that this invention be limited bythe claims and the equivalents thereof.

1. A dispatch server comprising: a data store having one or more application service definitions, wherein each application service definition includes a service name and one or more service data entries for a service registered with the dispatch server and located on an application server coupled to the data store; and a dispatch processor operatively coupled to the data store, wherein the dispatch processor is programmed to translate a service request into an application request, the service request being received from a client and including a name of the dispatch server that is provided by the client and a name of the service registered with the dispatch server, wherein the translation is at least partially based on one of the application service definitions, wherein the dispatch processor is to redirect the application request back to the client without processing the application request and without sending the application request to the application server having the service to be invoked by the service request; and wherein the application request includes only the application request relevant to the service to be invoked by the service request.
 2. The dispatch server of claim 1, wherein the dispatch processor is further programmed to subsequently translate the service request into a different application request, wherein the subsequent translation is at least partially based on a changed application service definition.
 3. The dispatch server of claim 1, wherein the dispatch processor is further programmed to manage a user interface, wherein the user interface includes a service registration interface, a service modification interface, and a service deletion interface.
 4. The dispatch server of claim 1, wherein the dispatch server is located on the World Wide Web.
 5. A method for accessing an application owner, the method comprising: receiving a service command from a requestor at a dispatch server, the service command including a name of the dispatch server that is provided by the requestor and a service name for a service registered with the dispatch server; processing the service command on the dispatch server; translating the service command on the dispatch server into an application request, wherein the translation is at least partially based on a service definition stored on the dispatch server; and redirecting the application request to the requestor without processing the application request at the dispatch server and without sending the application request from the dispatch server to an application server having the service to be invoked by the service command, wherein redirecting the application request includes sending only the application request relevant to the service to be invoked by the service request.
 6. The method of claim 5, further comprising sending the application request from the requestor to the application owner.
 7. The method of claim 5, wherein the processing of the application request comprises: sending the application request from the dispatch server to the application owner; sending an application response from the application owner to the dispatch server; and sending the application response from the dispatch server to the requestor.
 8. The method of claim 5, wherein the processing of the service command includes validating the service command, and checking the service command for parameters.
 9. The method of claim 5, wherein the service command includes a Universal Resource Locator.
 10. A method for accessing a complex web link, the method comprising: receiving a service request from an end-user at a dispatch server, the service request including a name of the dispatch server that is provided by the end user and a service name for a service registered with the dispatch server; translating the service request into a complex application command, wherein the translating is at least partially based on a service definition stored on the dispatch server; redirecting the complex application command from the dispatch server to the end-user without processing the complex application command at the dispatch server and without sending the complex application command from the dispatch server to a service provider having the service to be invoked by the service request, and wherein redirecting the complex application command includes sending the complex application command relevant to the service to be invoked by the service request; sending the complex application command from the end-user to the service provider; and sending an application response from the service provider to the end-user.
 11. A system comprising: a dispatch server comprising: a data store; and a processor programmed to translate a service request into an application command, wherein the translation is at least partially based on a service definition stored in the data store and the processor is operable to redirect the application command back to a service user operatively coupled to the dispatch server without processing the application command and without sending the application command to an application server having a service to be invoked by the service command, wherein the application command includes only the application command relevant to the service to be invoked by the service command; and wherein the service user sends the service request to the dispatch server, wherein the service request includes a name of the dispatch server that is provided by the service user and a service name for a service registered with the dispatch server, and wherein the dispatch server translates the service request and redirects the application command to the service user.
 12. The system of claim 11, wherein the system is located on the World Wide Web.
 13. The system of claim 11, wherein the system further includes an independent service management server.
 14. The system of claim 13, wherein the independent service management server includes a processor programmed to manage a service registration interface, a service modification interface, and a service deletion interface.
 15. A computer-readable medium having instructions stored thereon to perform a computerized method comprising: receiving a service invocation from an end-user to a dispatch server, the service invocation including a name of the dispatch server that is provided by the end user and a service name for a service registered with the dispatch server; processing the service invocation on the dispatch server; translating the service invocation on the dispatch server into an application command, wherein the translating is at least partially based on a service definition stored on the dispatch server; and redirecting the application command to the end-user without processing the application command at the dispatch server and without sending the application command from the dispatch server to an application server having the service to be invoked by the service invocation, wherein redirecting includes sending only the application command relevant to the service to be invoked by the service invocation.
 16. The computer-readable medium of claim 15, wherein the processing of the service invocation includes validating the service invocation.
 17. The computer-readable medium of claim 15, wherein the processing of the service invocation includes checking the service invocation for parameters.
 18. A method for source routing on a web dispatch server, the method comprising: sending a service command from a requestor at the web dispatch server, the service command including a name of the web dispatch server that is provided by the requestor and a service name for a service registered with the web dispatch server; determining which application server that provides the requested service is geographically closest to the requestor; translating the service command into an application request, wherein the translating is at least partially based on the determination of the geographically closest application server; and redirecting the application request back to the requestor without processing the application request and without sending the application request to the application server having the service to be invoked by the service request, wherein the application request includes only the application request relevant to the service to be invoked by the service request.
 19. A computer-readable medium having instructions stored thereon, which when executed by a computer, cause the computer to perform a computerized method comprising: receiving a service request from a requestor at a dispatch server, the service request including a name of the dispatch server and a registered service name that is provided by the requestor and a service name for a service registered with the dispatch server; validating the service request; checking the service request for parameters; translating the service request on the dispatch server into an application request to an application server, wherein the translating is at least partially based on a service definition stored on the dispatch server; and redirecting the application request back to the requestor without processing the application request at the dispatch server and without sending the application request from the dispatch server to an application server having the service to be invoked by the service request, wherein the application request includes only the application request relevant to the service to be invoked by the service request.
 20. The dispatch server of claim 1, wherein the application request includes a complex address. 